From: Xiubo Li <xiubli@xxxxxxxxxx> check_write_begin() will unlock and put the folio when return non-zero. So we should avoid unlocking and putting it twice in netfs layer. At the same time pass a **folio to check_write_begin(), in which the folio should be cleared after being put. URL: https://tracker.ceph.com/issues/56423 Signed-off-by: Xiubo Li <xiubli@xxxxxxxxxx> --- fs/afs/file.c | 2 +- fs/ceph/addr.c | 11 ++++++----- fs/netfs/buffered_read.c | 18 ++++++++++-------- include/linux/netfs.h | 2 +- 4 files changed, 18 insertions(+), 15 deletions(-) diff --git a/fs/afs/file.c b/fs/afs/file.c index 42118a4f3383..afacce797fb9 100644 --- a/fs/afs/file.c +++ b/fs/afs/file.c @@ -375,7 +375,7 @@ static int afs_begin_cache_operation(struct netfs_io_request *rreq) } static int afs_check_write_begin(struct file *file, loff_t pos, unsigned len, - struct folio *folio, void **_fsdata) + struct folio **folio, void **_fsdata) { struct afs_vnode *vnode = AFS_FS_I(file_inode(file)); diff --git a/fs/ceph/addr.c b/fs/ceph/addr.c index 8095fc47230e..cf909b08907f 100644 --- a/fs/ceph/addr.c +++ b/fs/ceph/addr.c @@ -63,7 +63,7 @@ (CONGESTION_ON_THRESH(congestion_kb) >> 2)) static int ceph_netfs_check_write_begin(struct file *file, loff_t pos, unsigned int len, - struct folio *folio, void **_fsdata); + struct folio **folio, void **_fsdata); static inline struct ceph_snap_context *page_snap_context(struct page *page) { @@ -1280,18 +1280,19 @@ ceph_find_incompatible(struct page *page) } static int ceph_netfs_check_write_begin(struct file *file, loff_t pos, unsigned int len, - struct folio *folio, void **_fsdata) + struct folio **folio, void **_fsdata) { struct inode *inode = file_inode(file); struct ceph_inode_info *ci = ceph_inode(inode); struct ceph_snap_context *snapc; - snapc = ceph_find_incompatible(folio_page(folio, 0)); + snapc = ceph_find_incompatible(folio_page(*folio, 0)); if (snapc) { int r; - folio_unlock(folio); - folio_put(folio); + folio_unlock(*folio); + folio_put(*folio); + *folio = NULL; if (IS_ERR(snapc)) return PTR_ERR(snapc); diff --git a/fs/netfs/buffered_read.c b/fs/netfs/buffered_read.c index 42f892c5712e..308c2ad4da8e 100644 --- a/fs/netfs/buffered_read.c +++ b/fs/netfs/buffered_read.c @@ -319,8 +319,8 @@ static bool netfs_skip_folio_read(struct folio *folio, loff_t pos, size_t len, * conflicting writes once the folio is grabbed and locked. It is passed a * pointer to the fsdata cookie that gets returned to the VM to be passed to * write_end. It is permitted to sleep. It should return 0 if the request - * should go ahead; unlock the folio and return -EAGAIN to cause the folio to - * be regot; or return an error. + * should go ahead; otherwise unlock, put and clear the folio and then return + * an error, -EAGAIN will cause the folio to be regot. * * The calling netfs must initialise a netfs context contiguous to the vfs * inode before calling this. @@ -348,13 +348,14 @@ int netfs_write_begin(struct netfs_inode *ctx, if (ctx->ops->check_write_begin) { /* Allow the netfs (eg. ceph) to flush conflicts. */ - ret = ctx->ops->check_write_begin(file, pos, len, folio, _fsdata); + ret = ctx->ops->check_write_begin(file, pos, len, &folio, _fsdata); if (ret < 0) { trace_netfs_failure(NULL, NULL, ret, netfs_fail_check_write_begin); if (ret == -EAGAIN) goto retry; - goto error; + goto error_unlocked; } + BUG_ON(!folio); } if (folio_test_uptodate(folio)) @@ -375,7 +376,7 @@ int netfs_write_begin(struct netfs_inode *ctx, NETFS_READ_FOR_WRITE); if (IS_ERR(rreq)) { ret = PTR_ERR(rreq); - goto error; + goto error_locked; } rreq->no_unlock_folio = folio_index(folio); __set_bit(NETFS_RREQ_NO_UNLOCK_FOLIO, &rreq->flags); @@ -402,12 +403,12 @@ int netfs_write_begin(struct netfs_inode *ctx, ret = netfs_begin_read(rreq, true); if (ret < 0) - goto error; + goto error_locked; have_folio: ret = folio_wait_fscache_killable(folio); if (ret < 0) - goto error; + goto error_locked; have_folio_no_wait: *_folio = folio; _leave(" = 0"); @@ -415,9 +416,10 @@ int netfs_write_begin(struct netfs_inode *ctx, error_put: netfs_put_request(rreq, false, netfs_rreq_trace_put_failed); -error: +error_locked: folio_unlock(folio); folio_put(folio); +error_unlocked: _leave(" = %d", ret); return ret; } diff --git a/include/linux/netfs.h b/include/linux/netfs.h index 1773e5df8e65..88c4eb85c6f7 100644 --- a/include/linux/netfs.h +++ b/include/linux/netfs.h @@ -214,7 +214,7 @@ struct netfs_request_ops { void (*issue_read)(struct netfs_io_subrequest *subreq); bool (*is_still_valid)(struct netfs_io_request *rreq); int (*check_write_begin)(struct file *file, loff_t pos, unsigned len, - struct folio *folio, void **_fsdata); + struct folio **folio, void **_fsdata); void (*done)(struct netfs_io_request *rreq); }; -- 2.36.0.rc1
